I'm deaf and even my doctor and the office allowed me to go in without a mask. I had a sign language interpreter but she wore a clear plastic mask that covered her whole face, not just the mouth area.

I have a good relationship with my interpreter and it was my first time seeing her after the pandemic started. She was shocked to see me walk in without a mask and she asked me to put my mask on. I told her that I'm not required to per the state's mandate mask policy. Even showed her the exemption and she said, "Damn you lucky bastard! I'm sweating with this stupid mask on my face!"

You and your father would need to learn the Americans with Disabilities Act law if you haven't, and understand your father's rights for necessary accommodations. If your father is fully deaf, he should be using a sign language interpreter and not rely on you if you're interpreting for him. Nothing wrong with you but it's wrong to use a family member as an interpreter because it's not your job. The doctor's office is responsible to provide one for your father.

If you have any questions, let me know as I'm profound deaf since I was a baby and have gone through this situation MANY times.